Electrical switches are components in a circuit which create (switch state “ON” or ON state) or break (switch state “OFF” or OFF state) an electrically conductive connection by means of internal, electrically conductive contacts. In the case of a current-carrying connection that is to be broken, current flows through the contacts until these are separated. If an inductive current circuit through a switch is broken, the flowing current cannot directly go to zero. In this case, an arc forms between the contacts. The arc is a gas discharge in a non-conductive medium, for example air. In switches in alternating current service (AC), the arc is quenched regularly at the zero-crossing point of the alternating current. Due to the lack of a zero crossing of the current, stable burning arcs occur in switches in direct current (DC) service, so long as the arc voltage is distinctly smaller than the operating voltage, when contacts are separated (switching off). When the circuit is operated with sufficient current and voltage (typically at over 1 A and over 50V), the arc will not extinguish on its own. For this purpose, quenching chambers are employed in such switches for quenching the arc. The arcing time (the duration of the arc burning) should be kept as short as possible, because the arc generates a significant amount of heat, and it burns off the contacts and/or generates thermal load on the switching chamber in the switch and this reduces the service life of the switch. In case of two pole or multi-pole switches with two or more switching chambers, the arcs generate a corresponding higher amount of heat than in case of one pole switches. It is especially important in this case that the arc is quenched quickly.
As a rule, quenching of the arc is accelerated by the use of a magnetic field that is polarized so that a driving force is exerted on the arc in the direction of the quenching chamber. Here, the magnitude of the driving force depends on the strength of the magnet or magnets. Permanent magnets are generally used to create a strong magnetic field. Unfortunately, the driving force of the magnetic field in the direction of the quenching chamber only occurs when the current flows in a particular direction. In order to prevent switch installation errors due to polarity or if switches are needed for both current directions, switches having a quick quenching process for arcs occurring between the open contacts during opening of the switch, that is independent of the respective polarity, would be desirable. This quenching function would be especially desirable in two pole switches with a structure not considerably more complex than one pole switches.